Many mail programs like for example Thunderbird have a built-in spam filter. The main difference from this to most central spam filters is that it gets trained by the user and thus is adjusted to what the users typically receives as spam and ham and what the users considers spam in the first place - e.g. some like news letters, others hate these.
Most of the time buffer overflows occur when we have strcpy(dest, src) in the source code.
Now, when you give input having null bytes, which you can't avoid because of ascii armor (shown in below input example), the input data after null bytes will be omitted from getting copied to stack area rendering the overflow unsuccessful. Note that target program may ...
You should insert this user into your database uniquely for each installation instead of hard coding the account or at least give the ability to disable the account as well as reset the accounts password. You cannot begin to predict how this backdoor admin account you are creating could be abused in the future. Maybe your company's sensitive files are ...
Sounds like you need the Responsible Disclosures method
in which a vulnerability is disclosed only after a period of time that allows for the vulnerability or issue to be patched
So contact the maintainer of the package first , and allow them time to fix it before publishing your findings